TWI481268B - Method of handling cell change and related apparatus - Google Patents

Description

Method for treating cell replacement and related device

The present invention relates to a method and a communication device for a wireless communication system, and more particularly to a method and a communication device for a wireless communication system that can improve a cell replacement mechanism.

Inter-radio-access-technology (Inter-RAT) involves the connection of a network from one wireless access technology to another wireless access technology to a mobile communication device. Cross-radio access technology may result in conversions due to Handover or Cell Reselection. In the case of cell reselection, the client will connect with cells of different wireless access technologies, among which the commonly used wireless access technologies are, for example, Global System for Mobile communications (GSM)/increased data rate. Enhanced Data Rates for GSM Evolution (EDEG), Universal Mobile Telecommunications System (UMTS), and Long-Term Evolution (LTE).

A cell replacement indicator program that leaves the GSM/EDEG Radio Access Network (GERAN) cell, such as a network-controlled cell reselection, through a packet containing cells of Target Cell information. The PACKET CELL CHANGE ORDER message begins. When receiving the packet cell replacement indication message, the user equipment (User Equipment, UE) starts a timer T3174 and selects the target cell to establish a connection. If the timer T3174 expires before the completion of the establishment of the Radio Resource Control (RRC) connection, the cell replacement indication procedure is regarded as a failure, and the mobile station (MS) returns to the GERAN cell. In addition, when the mobile communication station access target cell is rejected (such as the mobile communication station receives an IMMEDIATE ASSIGNMENT REJECT message, a PACKET ASSIGNMENT REJECT message, or a universal terrestrial wireless access network) One of the (UTRAN) cells, the RRC CONNECTION REJECT message, is also considered a failure.

A cell replacement indication procedure that leaves the cells of the universal mobile communication system begins with a message from the CELL CHANGE ORDER FROM UTRAN message, in which the network cell replacement indication message is received from the universal terrestrial radio. Contains information about target cells. Upon receiving the global cell access network cell change indication message, the mobile communication station initiates a timer T309 and selects the target cell to establish a radio resource control connection. If the timer T309 expires before the establishment of the RRC connection is completed, the cell replacement indication procedure is considered a failure and the mobile communication station returns to the UMTS cell. In addition, the cell replacement indicator procedure was also considered a failure when the mobile communication station access target cell was rejected. As can be seen from the above, the timers T3174 and T309 provide one of the expiration dates of the cell replacement indicating program.

When the UE performs a cell replacement indication procedure to switch from other radio access technologies (such as GSM/UMTS) to a long term evolution cell, ie, an enhanced Evolved UMTS Terrestrial Radio Access (E-UTRA) cell, The UE enters the long-term evolution cell in a radio resource control idle state (RRC_IDlE state), and then performs a random access procedure to communicate with the Evolved Node-B in the long-term evolution cell. Link synchronization and completion of the RRC connection setup procedure. The random access procedure is a technique well known to those skilled in the art, and thus its detailed description is omitted here. If the cell replacement indicator fails, the client returns to the source cell. In addition, the Long Term Evolution system utilizes several timers to access the Barring time. A timer T302 is used to time the RRC connection congestion time of the Mobile originating call/Mobile terminating call or the Mobile originating signaling; a timer T303 is used to time the user. The RRC connection congestion time of the terminal is sent; a timer T305 is used to time the RRC connection congestion time for the active signaling transmission of the UE. In the RRC connection establishment procedure, the long-term evolution cell in the congestion state can reject an RRC connection request by transmitting an RRC CONNECTION REJECT message. In this case, the UE must set a waiting time to the timer T302, wherein the waiting time is included in the RRC Connection Reject message. In other words, the access lockout time can be reflected by the timer T302.

In the prior art, the cell replacement instruction procedure of the long-term evolution cell is not clearly described and recorded, and therefore, the user terminal may face the following four cases.

In the first case, when performing data transmission (such as staying in a packet transmission mode of the GERAN system), if the UE receives a cell replacement indication, an RRC connection must be established with the target long term evolution cell as early as possible. However, the target long-term evolutionary cells may be temporarily blocked due to user-side signaling or active signaling, and the access blocking time may be too long, so that after the cell replacement, the user-side data transmission is seriously delayed. Affect the continuity and quality of the service.

In the second case, the UE receives a packet cell replacement indication message under a GERAN (GSM/EDEG Radio Access Network) cell and operates in a packet transmission mode to change to an EUTRA cell. At this point, the UE initiates timer T3174, which is set to 15 seconds. Next, the UE selects the EUTRA cell and performs a random access procedure to transmit an RRC Connection Request message to the EUTRA cell. The contention resolution of the user obtains random access, that is, the UE detects a temporary cellular wireless network temporary authentication (Temporary C-RATI) in a random access response (Random Access Response), and receives In the packet, after obtaining the corresponding contention resolution identity (Userion Resolution Identity), the user sees the cell replacement indication program succeeding, and stops the timer T3174. However, the EUTRA cell responds with an RRC CONNECTION REJECT message, which may include one of the waiting times between 1 and 16 seconds. If the UE initiates the timer T302, which is set to a waiting time of 8 seconds, the UE cannot enter the EUTRA cell until the timer T302 expires. When T302 expires, the UE performs the RRC connection establishment procedure again. At this time, if the UE receives another RRC Connection Reject message again, and the RRC Connection Reject message contains a 10-second waiting time, the UE cannot obtain the EUTRA cell access right. It can be seen from the above that one of the EUTRAN congestion states may cause the total waiting time (18 seconds) of the UE to exceed the time limit of one of the timers T3174 (15 seconds), resulting in a delay in the client access.

In the third case, the UE receives a packet cell indication message under a GERAN cell and operates in a packet transmission mode to replace it with an EUTRA cell. First, the UE initiates a timer T3174 set to 15 seconds, and then the UE selects the EUTRA cell and performs a random access procedure to transmit an RRC Connection Request message. However, if the EUTRA cell reply contains an RRC Connection Reject message with a latency of 2 seconds, this indicates that the network controls cell reselection failure. However, the above waiting time is too short. From the standpoint of the client, the UE can quickly retransmit the RRC Connection Request message. Therefore, if the user returns to the original cell according to the above specifications, the chance of obtaining a better data transmission rate is lost.

In the fourth case, at a GERAN cell, and operating in one of the packet transmission modes, the client receives a packet cell indication message for replacement to an E-UTRA cell. At this time, the UE starts the timer T3174 set to 15 seconds, and selects the E-UTRA cell to transmit an RRC connection request message. If the E-UTRA cell is in a stagnation state, the user initiates the timer T303 or T305 when accessing the E-UTRA cell. In this case, the client cannot perform a random access procedure due to the access blocking of the client (T303) or the client's active signaling (T305). If the timer T303 or T305 is greater than 15 seconds, the UE cannot access the E-UTRA cells before the timer T3174 expires. In short, if the time of timer T303 or T305 is greater than the waiting time of timer T3174, it will inevitably cause the failure of the cell replacement procedure. After the timer T3174 expires, the UE returns to the GERAN cell and transmits a PACKET CELL CHANGE ORDER FAILURE message. In the above case, the UE prohibits access to the EUTRA cells during the timer T3174 timing and must wait until the timer T3174 expires to return to the original cells.

The prior art will only determine that the cell replacement indicator has failed when receiving an access denied message (such as an immediate assignment rejection message). The prior art does not consider the length of access blocking time of the target cell, thus causing long delays in data transmission of the client.

Accordingly, the present invention provides a method of processing a radio access technology cell replacement and associated communication device to avoid the above problems.

The present invention discloses a method for processing cell replacement for a mobile device, the method comprising: performing a cell replacement indicating program to change cells from one source of a first wireless access technology to a second wireless access technology One of the target cells; and when a return condition for access blocking of the target cell is met, the cell replacement indicating program is judged to have failed.

The present invention further discloses a communication device for processing cell replacement, the communication device comprising: a computer readable recording medium and a processor. The computer-readable recording medium is used to store a program corresponding to a process, and the processor is coupled to the computer-readable recording medium for processing the program to execute the process, wherein the process includes: performing a cell replacement indicating program for replacing cells from a source of a first wireless access technology to a target cell of a second wireless access technology; and judging when a return condition for access blocking of the target cell is met The cell replacement indicator failed.

Please refer to Figure 1, which is a schematic diagram of a cell replacement. In Fig. 1, a cell 12 is a serving cell of a mobile device 10, and cells 12 and 14 support different radio access technologies. In addition, the mobile device 10 can support the radio access technology of the cells 12 and 14. The cell 12 supports a Universal Mobile Telecommunications System (UMTS) radio access technology, a Global System for Mobile communications (GSM) or an GSM evolution technology (Enhanced Data Rates for GSM). Evolution, EDEG) wireless access technology, and controlled by a base station (such as Node B). The cell 14 supports a Long-Term Evolution (LTE) radio access technology and can be controlled by an Evolved-Node B under LTE radio access technology, which provides a UE-to-radio interface. The mobile device 10 can be regarded as a user equipment (UE) or a mobile station (MS), which supports the above-mentioned wireless access technology, and can be a mobile phone or a computer system. The mobile device 10 can measure the quality of the communication, such as the received strength of the wireless signal, or the quality of the channel/frequency, and generate an associated measurement report to the serving cell. When the equivalent test report indicates a poor communication quality, the cell 12 can transmit a cell replacement indicator to initiate a cell replacement indicator procedure to assign the cell 14 to the mobile device 10. At the time of cell replacement, cells 12 and 14 are regarded as a source cell and a target cell, respectively. When the cell 12 is a GSM/GERAN cell, the cell replacement indication is a PACKET CELL CHANGE ORDER message. Alternatively, when the cell 12 is a UMTS cell, the cell replacement indication is a CELL CHANGE ORDER FROM UTRAN message. When receiving the cell replacement instruction, the mobile device 10 performs a cell replacement instruction procedure to access the cells 14. In general, after the mobile device 10 selects the cell 14, a random access procedure is performed to obtain uplink synchronization and establish a Radio Resource Control (RRC) connection. Further, when the cell replacement instructing procedure is started, the mobile device 10 starts a timer to provide a cell replacement indicating program for an expiration date. When cell 12 is a GSM/GERAN cell, the timer is T3174, and when cell 12 is a UMTS cell, the timer is T309. When the mobile device 10 receives a RRC CONNECTION SETUP message, this indicates that the target cell accepts the RRC connection, so the mobile device 10 stops the timer and determines that the cell replacement indication procedure is completed. When the timer (T3174 or T309) expires before the completion of the RRC connection establishment procedure, the mobile device 10 returns to the cell 12. In addition, the cell 14 can perform an access blockade with respect to a mobile originating call, a mobile terminating call, a mobile originating signaling, or a cell replacement indication. For the access blockade of the cell 14, the mobile device 10 establishes a return condition and, when the return condition is met, determines that the cell replacement indicating procedure has failed.

When the mobile device 10 meets the return condition, it indicates that the cell replacement indicating procedure has failed due to the cell 14 access blockade, in which case the mobile device 10 returns or reselects the cell 12 and transmits a cell replacement indication failure message to the cell 12 . The cell replacement indication failure message described above includes a failure message indicating that the cell replacement indication procedure failed due to the access blockade of the cell 14. In addition, the failure information may further include an access blocking time, and one of the control cells 12 may determine whether or when to activate the cell replacement indicating procedure of the mobile device 10 according to the access blocking time. After the above-mentioned access blocking time, the base station may again transmit a cell replacement indication message (such as a packet cell replacement indication/from the universal terrestrial wireless access network cell replacement indication message) to the mobile device 10 to instruct the mobile device 10 to perform the re-operation. Cell replacement indicator procedure.

Please refer to FIG. 2, which is a schematic diagram of a communication device 20 according to an embodiment of the present invention. The communication device 20 can be a mobile device 10 that supports LTE, UMTS, GSM, and GERAN Iu mode systems. The communication device 20 includes a processor 200, a computer-readable recording medium 210, a communication interface unit 220, and a control unit 230. The readable recording medium 210 can be any data storage device for storing a program 214 and reading and processing the program 214 through the processor 200. The computer readable recording medium 210 can be a Subscriber Identity Module (SIM), a Universal Subscriber Identity Module (USIM), a Read-Only Memory (ROM), and a random access memory. Random-Access Memory (RAM), CD-ROM, Magnetic Tapes, Hard Disks, optical data storage devices, and carrier waves (eg, Internet data transmission) ). Based on the processing results of processor 200, control unit 230 controls the state of communication interface unit 220 and its associated operations and communication device 20. The communication interface unit 220 is preferably a wireless transceiver for exchanging wireless signals with a remote communication device such as a base station.

The above return conditions can be established according to the following three aspects: (1) according to receiving a message indicating access blocking of a target cell under a pure packet switched radio access technology (such as LTE radio access technology), (2) According to a waiting time, it indicates the access blocking time of the target cell, or (3) according to a timer, used to time the access blocking of the target cell.

Please refer to FIG. 3, which is a flowchart of a process 30 according to the first embodiment of the present invention. The process 30 is for a client (or a mobile communication station) for processing a cell replacement based on a return condition, wherein the return condition is based on the received message. The process 30 can be compiled into the program 214 and includes the following steps:

Step 300: Start.

Step 310: When receiving a cell replacement instruction instruction of one of the non-long-term evolution cells, perform a cell replacement indicating program to change from the non-long-term evolutionary cell (source cell) to a long-term evolution cell (target cell).

Step 320: When receiving one of the messages of the long term evolution radio access technology, and the message indicates long term evolution cell access blocking, it is determined that the cell replacement indication procedure fails.

Step 330: End.

According to the process 30, the UE performs a cell replacement instructing procedure to select a long-term evolution cell, and when receiving a message indicating an access blockade of the long-term evolution cell, determines that the cell replacement instruction procedure has failed. In addition, after selecting the long-term evolution cell, the UE performs a random access procedure to complete a radio resource control connection establishment procedure. It is worth noting that if long-term evolutionary cells experience access congestion, they reject all radio resource control connections. In this case, the message transmitted by the Long Term Evolution Radio Access Technology is a RRC CONNECTION REJECT message indicating that the RRC connection establishment procedure has failed. In other words, if the RRC connection establishment procedure performed by the Long Term Evolution Radio Access Technology fails due to access blocking, the UE determines that the cell replacement indication procedure has failed. Therefore, during the cell replacement instruction procedure, the UE does not re-establish the RRC connection establishment procedure.

Among them, the random access program includes a program that competes with other users to obtain priority access to long-term evolution cells. In addition, the aforementioned non-long-term evolution cells may be a GSM/GERAN/UMTS cell, and the user may initiate a timer T3174/T309. When the UE obtains the contention result of the random access procedure, the timer T3174/T309 continues to count. When the RRC connection establishment procedure fails because the access lockout fails, the UE stops the timer T3174/T309. The client may also start a timer for timing access lockout time, which may be T302, T303 or T305, and when the timer expires or stops, the user end to the upper communication layer (for example, an application) The layer or a Non Access Stratum layer informs that the access lock has been released.

In addition, after determining that the cell replacement instruction procedure has failed, the client returns to the non-long-term evolutionary cell and performs the steps performed by the mobile device 10 after returning to the cell 12. Through the failure information of the process 30 and the foregoing transmission to the non-long-term evolutionary cell, the user terminal will not encounter a serious data transmission delay and will not suffer from the ping-pong situation except that the access of the long-term evolutionary cell is not blocked. The so-called ping-pong situation, that is, the user side performs the cell replacement instruction procedure multiple times, but the cell replacement instruction program continuously fails due to the access blockade, and continues to travel between the two cells.

For example, when performing data transmission (such as a packet transmission mode under a GERAN system), the UE receives a cell replacement indication and then immediately attempts to establish a radio resource control connection with the target long-term evolutionary cell in the occlusion state. According to the concept of the process 30, when the long-term evolution cell indicates the user-side access blockade, the user terminal determines that the cell replacement indication fails, and then returns to the source cell to restart the data transmission at the source cell, thereby avoiding the data transmission delay problem. In addition, the ping-pong situation can be avoided, so that the user does not block the access, but the cell replacement instruction procedure that must fail is continuously performed. Therefore, the continuity/quality of service use can be improved.

Please refer to FIG. 4, which is a flowchart of a process 40 according to a second embodiment of the present invention. The process 40 is for a user terminal (or a mobile communication station) for processing a cell replacement, wherein the return condition is established according to a waiting time state. The process 40 can be compiled into the program 214 and includes the following steps:

Step 400: Start.

Step 410: Perform a cell replacement indicating program to change from a non-long-term evolution cell to a long-term evolution cell, and when receiving a cell replacement instruction instruction transmitted by the non-long-term evolution cell, start a timer TA to provide The cell replacement indicator is one of the expiration dates.

Step 420: Receive one of the waiting times of the long term evolution cell access blockade.

Step 430: When the waiting time is greater than or equal to one of the remaining time of the timer TA, it is determined that the cell replacement indicating program fails.

Step 440: End.

According to the process 40, when the waiting time of the received long-term evolution cell is greater than or equal to the remaining time of the timer TA, the UE determines that the cell replacement indication procedure has failed. On the other hand, when the waiting time is less than the remaining time of the timer TA, the UE determines that the cell replacement indicating program is still in the active state. In addition, when a waiting time is received, the UE can initiate a timer TB, which is used to time the waiting time. Preferably, the timer TA is T3174/T309; the timer TB is T302.

The waiting time may be included in one of the radio resource control connection rejection procedures (RRC CONNECTION REJECT) messages performed by the UE and the long term evolution cell. In this case, after determining that the cell replacement indication program is still in the active state, the UE performs another radio resource control connection establishment procedure when the timer TB expires. If another waiting time is received while another radio resource control connection establishment procedure is being performed, the UE compares the waiting time of the latest reception with the current remaining time of the timer TA. The comparison and judgment of the waiting time can be repeated as described above until the user terminal determines that the cell replacement indicating program has failed or successfully establishes a radio resource control connection with the long term evolution cell.

When the waiting time is greater than or equal to the remaining time of the timer TA, it means that one of the long-term evolution cells has an access blocking time greater than the expiration date of the cell replacement indicating program. In other words, since the expiration time of the timer TA is earlier than the expiration time of the waiting time, the cell replacement instructing program must be judged as a failure. In this case, the UE can use the process 40 to promptly determine that the cell replacement indication procedure has failed without waiting for the timer TA or the expiration time of the waiting time. After determining that the cell replacement indication procedure has failed, the UE can directly return to the non-long-term evolution cell to avoid the user encountering a long transmission delay.

When the waiting time received is less than the remaining time of the timer TA, the UE has another chance to access the long-term evolution cells to obtain better communication service quality, such as obtaining a higher data transmission rate.

For example, a user operating under a GERAN cell and operating in a packet transmission mode receives a PACKET CELL CHANGE ORDER message to exchange cells to a long term evolution cell. The client initiates a timer T3174, which is set to 15 seconds, and then the UE selects the long term evolution cell and performs a random access procedure to transmit a RRC CONNECTION REQUEST message. Due to the access blocking of the long-term evolution cell, the UE receives the RRC CONNECTION REJECT message and starts the timer T302, and its timing is set to a waiting time. Assume that the interval between receiving the packet cell replacement indication message and receiving the RRC connection rejection message is negligible. If the waiting time is 16 or 15 seconds, it is known that it is greater than or equal to the timer T3174, and the UE determines that the cell replacement indication procedure has failed. And return GERAN cells. After the user selects the GERAN cell, a PACKET CELL CHANGE ORDER FAILURE message is sent to notify the GERAN cell that the cell replacement instruction procedure failed.

On the other hand, if the waiting time is less than 15 seconds, after the timer T302 expires, the UE performs the RRC connection establishment procedure again. In the latest RRC connection establishment procedure, if the UE receives another RRC connection rejection message containing another waiting time, the UE determines whether the cell replacement indication procedure has failed according to the latest received waiting time. In this case, it is assumed that the remaining time of the timer T3174 is 10 seconds, and if the latest received waiting time is 10 to 16 seconds, the UE determines that the cell replacement indication procedure has failed, and performs the third radio resource control connection. Establish procedures to achieve better communication service quality. As can be seen from the above, by comparing the waiting time with the timer T3174, the UE can reduce the delay of data transmission.

Please refer to FIG. 5, which is a flowchart of a process 50 according to a third embodiment of the present invention. The process 50 is for a client (or a mobile communication station) for handling a cell replacement, wherein the return condition is established according to an access lockout timer. The process 50 can be compiled into the program 214 and includes the following steps:

Step 500: Start.

Step 510: When receiving a cell replacement instruction instruction transmitted by the non-long-term evolutionary cell, perform a cell replacement indication procedure to change from a non-long-term evolution cell to a long-term evolution cell, and start a timer TC to provide The cell replacement indicator is one of the expiration dates.

Step 520: When the long term evolution cell is selected, a timer TD is started to time the access blocking time.

Step 530: When one of the initial time values of the timer TD is greater than or equal to one of the remaining time of the timer TC, it is determined that the cell replacement indicating program fails.

Step 540: End.

According to the process 50, the UE uses the timer TC to time the expiration date of the cell replacement indicating program, and uses the timer TD to time the access blocking time of the long-term evolution cell. When the initial time value of the timer TD (ie, the timing period) is greater than or equal to the remaining time of the timer TC, the UE determines that the cell replacement indication procedure has failed. The initial time value of the timer TD is greater than or equal to the remaining time of the timer TC, which represents that the access blocking period of the long-term evolutionary cell is greater than the expiration date of the cell replacement indicating procedure. Therefore, the cell replacement indicator must fail. In this case, through the process 50, the UE can determine that the cell replacement indication procedure has failed early. After determining that the cell replacement indication procedure has failed, the client can return to the non-long-term evolution cell to avoid a serious delay in the data transmission of the client.

In addition, when the initial time value is less than the remaining time of the timer TC, the UE determines that the cell replacement indicating program is still in an active state. After that, the UE can perform a RRC connection establishment procedure or a random access procedure when the timer TD expires.

Preferably, the timer TD is T302, T303 or T305; the timer TC is T3174/T309. When the timer TD is T302, the initial time value of T302 can be set to a waiting time, which is included in a radio resource control connection reject message of one of the radio resource control establishment procedures between the UE and the long term evolution cell.

In summary, the embodiment of the present invention provides a method for the UE to determine whether the cell replacement indication procedure fails according to the received access blocking indication message, the waiting time, or an independent timer, so as to reduce the long-term delay of the data transmission of the client.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10. . . Mobile device

12, 14. . . cell

20. . . Communication device

200. . . processor

210. . . Computer readable recording medium

220. . . Communication interface unit

230. . . control unit

214. . . Program

30, 40, 50. . . Process

300, 310, 320, 330, 400, 410, 420, 430, 440, 500, 510, 520, 530, 540. . . step

Figure 1 is a schematic diagram of cell replacement in a wireless communication system.

FIG. 2 is a schematic diagram of a communication device according to an embodiment of the present invention.

FIG. 3 is a flow chart of a process of the first embodiment of the present invention.

Figure 4 is a flow chart showing a flow of a second embodiment of the present invention.

Figure 5 is a flow chart showing a flow of a third embodiment of the present invention.

30. . . Process

300, 310, 320, 330. . . step

Claims (15)

A method for processing a cell replacement for use in a mobile device, the method comprising: performing a cell replacement indicating program to replace a cell from a source of a first wireless access technology to a target of a second wireless access technology a cell; when performing the cell replacement indicating program, initiating a first timer; receiving, from the target cell, a message indicating one of waiting times of access blocking of the target cell; when receiving the message, initiating a first a second timer, wherein an initial time value of the second timer is the waiting time; and if the initial time value of the second timer is greater than or equal to a remaining time of the first timer, determining the cell replacement indication The program failed. The method of claim 1, wherein the second timer is T302, T303 or T305. The method of claim 1, wherein when the second timer expires, a RRC connection establishment procedure or a random access procedure is performed. A method for processing a cell replacement for use in a mobile device, the method comprising: performing a cell replacement indicating program to replace a cell from a source of a first wireless access technology to a target of a second wireless access technology a cell; when the cell replacement indicating program is performed, initiating a first timer having an initial time value; receiving, from the target cell, a message indicating one of waiting times of access blocking of the target cell; When the mobile device successfully completes the competition result, the first timer is continuously clocked. The method of claim 4, further comprising determining that the cell replacement indication procedure fails if the waiting time is greater than or equal to one of the remaining time of the first timer. The method of claim 4, further comprising: when receiving the message, initiating a second timer, wherein an initial time value of the second timer is the waiting time; and if the second timing The initial time value of the device is greater than or equal to the remaining time of one of the first timers, and it is determined that the cell replacement indicating program fails. A method for processing a cell replacement for use in a mobile device, the method comprising: performing a cell replacement indicating program to replace a cell from a source of a first wireless access technology to a target of a second wireless access technology The cell; if receiving a message, determining that the cell replacement indication procedure has failed, wherein the message indicates that the target cell access is blocked and is a message other than a RRC CONNECTION REJECT message. The method of claim 7, wherein the message indicates an access blockade of the client-side access blockade or active signaling transmission. The method of claim 7, wherein the determining step is performed if the radio resource control connection establishment procedure in the target cell of the second radio access technology fails due to the access block. The method of claim 7, further comprising a start timer T302 or T303 timing access lockout. The method of 4 or 7, wherein the second RAT is a long term evolution (LTE), when the first When the line access technology is an enhanced data rate GSM evolved wireless access network (GERAN) system, the first time is T3174, and the cell replacement indication procedure is transmitted through a packet replacement cell (PACKET CELL CHANGE ORDER) message. Initiating; or the second radio access technology is a long term evolution system, when the first radio access technology is a universal terrestrial wireless access network (UTRAN) system, the first time is T309, and the The cell replacement indicator program is initiated by a message from the CELL CHANGE ORDER FROM UTRAN message. The method of claim 11, further comprising a start timer T302 or T303 timing access block. After determining that the cell replacement instruction procedure has failed, the source cell is selected; and a cell replacement indication failure message is transmitted to the source cell. The method of claim 12, wherein the cell replacement indication failure message includes a failure message indicating that the access blockade of the target cell causes the cell replacement indication procedure to fail. The method of claim 12, further comprising receiving a cell replacement indication message of the source cell after an access lockout time to re-execute the cell replacement indication procedure, wherein the cell replacement indication message comprises a failure Information, the failure information contains the access lockout time. The method of claim 14, further comprising determining that the cell replacement indication procedure is completed when receiving a wireless resource connection establishment message of the target cell.